# Turn Pressure – Dive Planner — Scuba gas & no-deco calculator > Scuba dive planner for turn pressure, gas, and bottom time calculations. (iPhone/iPad app by RUSTAM ISMAILOV.) - Source: https://appshunter.io/ios/app/turn-pressure-dive-planner/id6801749776 (this page in markdown: same URL + `.md`) - Developer: [RUSTAM ISMAILOV](https://appshunter.io/developer/6799582362) - Category: Sports, Utilities - Price: Free - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 17.0 · 4 MB - Languages: American English - Released: 2026-09-01 - Data updated: 2026-10-08 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/turn-pressure-dive-planner/id6801749776/reviews.md ## What is Turn Pressure? Most divers were taught one number: surface on 50 bar, or 500 psi, no matter the depth, the cylinder, or who they're diving with. It's not that nobody plans — it's that the plan never changes with the dive. Turn Pressure runs the actual numbers instead. Tell it how deep you're going, what you're carrying and who's breathing it, and it gives you a turn pressure, the minimum gas to get two divers up from the deepest point, and a bottom time — before you kit up. It's a no-stop, recreational planner. It doesn't plan decompression dives, stage gases or bailout, and it isn't meant to run during the dive — plan with it on the boat or the night before, then go by your gauge and your computer in the water. WHAT MAKES IT DIFFERENT Minimum gas that scales. Most calculators hand you a flat reserve. Turn Pressure works from the volume two divers need to reach the surface, for your cylinder and your SCR — at 20 L/min, the same ascent from 30 m needs 45 bar from a 15-litre steel and 61 bar from an aluminium 80. Same dive, same divers, different tank, different number. A bottom-time limit for your gas, not just your air. Full Bühlmann ZH-L16C no-stop calculation for air, EAN28, EAN32 and EAN36, with gradient-factor presets from 30/70 to 100/100 — including 15/85 — defaulting to 40/85, so you can match whatever your computer is set to. Repeat dives use the dive you actually did. Tell it how deep you went and how long you were down, and it works out what nitrogen is still in you across your surface interval — instead of guessing at a dive it cannot see. If you don't tell it, it doesn't guess: it shows you nothing and says why. Two deep segments before the ascent. Deep first, then shallower — or the other way — and the gas, the turn pressure and the no-stop limit are planned across both, with minimum gas for each segment. An ascent you can brief. The way up is a ladder of levels — each with its own time and depth, labelled on the chart, with the gauge you leave it on — each a depth to hold or be shallower than. When the no-stop limit ends the deep part of a dive, the plan spends the remaining gas on the way up instead of sending you up with a full-looking gauge. One number, not two. Bottom time is whichever runs out first — your gas or your no-stop limit — and Turn Pressure tells you which one it was, so you know if you're gas-limited or NDL-limited before you're in the water. Your SCR (SAC), not an average off a chart. Type your own number, start from a tier, or work it out from one real dive's numbers — depth, time, cylinder, start and finish pressure. Turn Pressure keeps it as a dated list with a trend chart so you can watch it improve. Metric and imperial done properly. 100 ft and 130 ft, AL80 and HP100 — the numbers each system is actually dived in, not arithmetic conversions like 98 ft or "81 cu ft." EVERYTHING ELSE • Turn pressure on thirds, halves or all-usable gas • Single, or double/sidemount — 10 L and 12 L steel, aluminium 80, 15 L steel • Maximum operating depth for every mix, hard-blocked at ppO2 1.4; planning to 40 m, sea level only • Ascent rate you choose, 3 to 9 m/min — the reserve follows it and never shrinks • Two ascent profiles: NDL with a safety stop (a stepped ascent with 3 minutes at 5 m), or the Minimum Decompression Profile — 9 m/min to half your depth or 9 m, then 3 m/min, no stops — whose bottom times come from a published recreational schedule rather than from the model, and which plans EAN32 to 30 m because that is what the schedule covers • Saved briefs for the dives you run over and over • Share the plan as one picture — profile, bars per depth, minimum gas • Works with no signal, on any boat, anywhere Free. No account, no ads, no analytics, no network access at all — nothing leaves your phone. This is a planning tool, not a dive computer and not a decompression planner. Your training, your gauge and your computer decide the dive. Turn Pressure just does the arithmetic beforehand. ## Key features - Dynamic turn pressure calculation - Minimum gas reserve for two divers - Bottom time limit based on gas or NDL - Repeat dive planning with surface interval - Detailed ascent profiles - Personal SAC rate tracking - Metric and imperial unit support ## Frequently asked questions about Turn Pressure ### What is the main purpose of Turn Pressure? Turn Pressure is designed to calculate crucial dive planning parameters like turn pressure, minimum gas reserves for two divers, and bottom time limits. It helps divers plan their dives accurately before entering the water, ensuring they have sufficient gas and adhere to no-decompression limits. ### Does Turn Pressure support different gas mixes? Yes, Turn Pressure supports planning for air, EAN28, EAN32, and EAN36. It also allows for gradient-factor presets from 30/70 to 100/100, enabling users to match their dive computer settings. ### How does Turn Pressure handle repeat dives? For repeat dives, Turn Pressure accounts for the nitrogen remaining in your system based on your previous dive's depth and duration, and your surface interval. This provides a more accurate plan for subsequent dives rather than relying on general assumptions. ### Can Turn Pressure be used for decompression diving? No, Turn Pressure is strictly a no-stop, recreational planner. It does not plan decompression dives, stage gases, or bailouts, and is not intended for use during the dive itself. ### How does Turn Pressure calculate minimum gas reserves? Unlike other calculators that may provide a flat reserve, Turn Pressure calculates the minimum gas needed to ascend from the deepest point for two divers based on the actual cylinder volume being used. This ensures a more personalized and accurate reserve calculation. ### Does Turn Pressure have ads? No, Turn Pressure is ad-free. As a free application, it does not contain advertisements, allowing for an uninterrupted planning experience. ### What is the update frequency for Turn Pressure? The application was last updated on September 17, 2026, indicating a recent update. While specific update frequency isn't detailed, this suggests ongoing development and maintenance. ### What devices is Turn Pressure available on? Turn Pressure is currently supported on iPhones. Future expansion to other platforms like Android may be considered by the developer. ## Version history (last 5 releases) ### 1.8 — 2026-09-26 Minimum gas now comes from your own SCR: two divers breathing at your SCR × the conditions multiplier, from the depth you leave to the surface, never below 40 bar. When gas ends a deep segment, you leave it on the minimum gas, and the way up is breathed from it. The (?) beside the ascent explains your levels, the minimum gas as C × A × T worked on your own dive, and Leave at. Longer explanations open as a sheet you can read in full. Clearer wording throughout, every explanation checked against real plans. ### 1.7 — 2026-09-25 Every (?) behind a calculated figure now shows its formula: what goes in, where each value comes from, and how it is rounded. SCR, surface consumption rate, replaces SAC throughout, and the second level is now the second deep segment. Each depth in the profile shows the gauge you leave it on and the minimum gas there, rounded the same way. Where the two are the same, only the minimum gas shows. The turn pressure says where you reach it: at 30 m, or on the way up to 10 m. A plan with no time at depth says why and quotes the fill that buys a minute. A second deep segment is offered only at depths that plan. Minimum Decompression Profile: the bottom time counts from leaving the surface, and the ascent is 9 m/min to half your depth or 9 m, then 3 m/min. ### 1.6 — 2026-09-21 A second level of bottom time. Add a depth and minutes after your time at maximum depth — deeper or shallower — and the gas, the turn pressure and the NDL are planned across both before the ascent. Minimum gas for each level: what to leave the first level with, what to leave the second with, and the figure from 9 m up, on one line. The profile shows the gauge you leave each depth on, to the nearest 5 bar, on the card, in View details and on the shared picture. View details and the shared picture are the same page — starting fill, turn pressure, minutes and bars per depth, minimum gas — and the picture carries the App Store link and a QR code for a buddy. ### 1.5 — 2026-09-17 Who is diving now sits on the photo at the top of the page, under the title — one tap into the diver picker, with the source of their breathing rate beside the name. The strategy, limits and conditions tiles, and the cylinder tiles, take less of the screen: the same choices, without the empty space under them, so the plan is reached with less scrolling. VoiceOver announces when a plan is refused and why, and when the refusal clears. ### 1.4 — 2026-09-15 Time at max depth is now minutes you set, on a slider that runs up to the most your gas and your NDL allow — the maximum is printed beside it, with what caps it. The old percentage picker is gone, and so is the caption that tried to explain it. A new look for the plan page: a photo header, icons on every section, the choices as tiles, and a share button that exports the profile and every figure from the results as one picture for a buddy or a group chat. The ascent is drawn beside a hold-by-hold breakdown — maximum depth first, then each level — and View details opens it full screen with a third column: the gauge pressure you leave each depth on, walked from the same gas bill as the turn pressure. Minimum gas is one tile, with the reserve from 9 m up beside it where it applies, and a (?) on the ascent explaining why the levels are where they are. Smaller fixes: a scroll that starts on the fill slider no longer moves it, and the slider shows in red the fills the plan cannot use. ## Apps similar to Turn Pressure | App | Rating | Price | Category | | --- | --- | --- | --- | | [FencingDynamics](https://appshunter.io/ios/app/fencingdynamics/id6744992083) | — | Free | Sports | | [Dive Toolbox](https://appshunter.io/ios/app/dive-toolbox/id6759796903) | — | Free | Sports | | [Dive Plan](https://appshunter.io/ios/app/dive-plan/id496279549) | 1.8 (8) | Free | Sports | | [Wind Zero](https://appshunter.io/ios/app/wind-zero/id6443698578) | 5.0 (3) | Free | Sports | | [OSTConf](https://appshunter.io/ios/app/ostconf/id1404182943) | — | Free | Sports | | [Dive Kit: Deco Planner & Tools](https://appshunter.io/ios/app/dive-kit-deco-planner-and-tools/id6753089545) | 5.0 (1) | Free | Sports | ## More apps by RUSTAM ISMAILOV - [Four & Six Breathing Exercise](https://appshunter.io/ios/app/four-and-six-breathing-exercise/id6799582360) - [Time to Surface – Deco Planner](https://appshunter.io/ios/app/time-to-surface-deco-planner/id6803187271) - [Weights Check – Dive Weighting](https://appshunter.io/ios/app/weights-check-dive-weighting/id6806640499) - [Surface Interval – Dive Videos](https://appshunter.io/ios/app/surface-interval-dive-videos/id6813333816) All apps by RUSTAM ISMAILOV: https://appshunter.io/developer/6799582362 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-08.*